养护方式对负温条件下碱矿渣水泥砂浆强度的影响

Impacts of Maintenance Methods on the Strength of Alkali-activated Slag Cement Under Negative Temperature

研究了恒负温、一次冻结及预养护3种养护方式对碱矿渣水泥砂浆强度的影响,确定碱矿渣水泥-20℃条件下的临界受冻强度。实验结果表明:恒负温至-10℃时,碱矿渣水泥已经不能正常水化硬化;一次冻结降低了碱矿渣水泥各龄期的抗折和抗压强度;预养护6h的碱矿渣水泥便能在-20℃条件下继续发展强度。确定碱矿渣水泥的临界受冻强度为3 MPa。

For the purpose of determining resistant freezing critical strength of alkali-activated slag cement （AASC） under --20℃, researches were conducted about the impacts of three maintenance methods, i. e. constant negative temperature, straight freezing and pre-conservation, on its strength. The experiment leads to the following results： （1） when the constant negative temperature reaches -10℃, AASC cannot hydrate and harden normally any more; （2） with straight freezing, flexural strength and compressive strength of AASC in its each stage are reduced; （3） after 6 hours＇ pre-conservation, AASC can develop its strength even under -20℃. And the resistant freezing critical strength of AASC is determined as 3 MPa.